Hormones may be the culprits in slowing metabolism and causing weight gain. Recently a study conducted by the University of Melbourne revealed that for at least a year after dieting, a combination of hormonal changes endlessly signals the body to not only slow down metabolism, but also to increase appetite. Loss of body fat decreases the levels of a hormone produced by fat cells, known as leptin. The hormone drop causes the body to signal the brain that energy stores are running low, which leads to a decrease in metabolism and increase in appetite, thus the weight gain.

The dieter’s body rebels against weight loss if the hormones are leading to weight gain. People who tend to drastically lose weight gain bigger appetites, while burning fewer calories than an obese individual. The University of Melbourne study compared the levels of hormones in an average weight person and an obese person, and concluded that six out of nine hormones, in all probability, were more likely to boost hunger-creating properties.

Girls tend to gain weight after puberty/menopause. And hormones are to be blamed for that. During puberty/menopause, hormone levels in women fluctuate extensively. These hormones include estrogen and progesterone. Other reasons are lifestyle changes i.e lack of physical activity and lethargy which slows the metabolism. Thus, it is important to follow an active lifestyle and sudden weight gain should be a cause for concern for women during their puberty/menopause stage.

As far as men's weight and metabolism is concerned, there are about 8 hormones in men which can play havoc leading to weight gain. The most important hormone is testovirone. This hormone upholds muscle tone, volume and strength, by increasing metabolism and decreasing body fat. Other than this, thyroxine (T4). also helps in raising metabolism in men.

If I am genetically fat, hormone-wise, can my weight still be controlled? The answer is yes, to some extent. Genetic fat cells cannot be easily controlled by dieting, but that doesn’t mean you should give up on it. Stay away from highly processed foods such as white pasta, white rice, white bread as they shoot up the amount of insulin in the body, another hormone which leads to weight gain. If nothing seems to have worked, do get tested for thyroid-based hormonal deficiencies or imbalances. This deficiency leads to a decrease in metabolism, causing weight gain, specifically torso adiposity or belly fat.